The present invention concerns large rectangular balers, and, more particularly, concerns power transmission arrangements for driving the plunger and auxiliary functions of a balers for producing parallelepiped bales.
It is common practice to design so-called large square or rectangular balers so as to be driven from the PTO of the towing tractor. These drive arrangements often contain a flywheel for smoothing the power flow, however, after the PTO power is cut or stopped, it takes several seconds for the flywheel to stop because of its stored energy. Consequently, pick-up and feed components, as well as the plunger drive, continue to work. If the reason for stopping was because of a foreign object being fed into the baler, then the continued working of the baler components could result in damage to the baler. Also, if the operator stopped so as to inspect some malfunction of the baler, then the coasting parts could possibly endanger the operator if he came quickly to the baler once the PTO was turned off. An example of such a baler drive arrangement is disclosed in U.S. Pat. No. 4,135,444, issued Jan. 23, 1979.
One known large rectangular baler uses the tractor PTO to drive a shaft carrying a flywheel, this shaft in turn being coupled to a pump which supplies the fluid for driving both the plunger and various auxiliary functions of the baler. Thus, the respective hydraulic motors and/or cylinders used to drive the plunger and auxiliary functions continue to receive working fluid for a period of time after power to the PTO is cut off. Again, the time for these components to coast to a stop may be sufficient to permit damage to the baler or for an operator to get entangled in moving parts.
U.S. Pat. No. 2,644,283, issued Jul. 7, 1953, discloses a baler for making rectangular bales, with the plunger and wire tying shuttle being powered by hydraulic cylinders that are supplied by the same pump. Apparently, no flywheel is used in this design.
According to the present invention there is provided a novel drive arrangement, including a flywheel, for driving the plunger and auxiliary functions of a large rectangular or square baler.
An object of the invention is to provide a large rectangular baler with a drive arrangement including a main power shaft for powering the plunger and all of the remaining auxiliary functions, and including a flywheel which operates to even out the power flow at least to the plunger but is embodied so as not to cause the continued driving of the plunger once power is disconnected from the main power shaft.
A more specific object of the invention is to provide a drive arrangement as defined in the previous object wherein the flywheel is associated only with the plunger drive, the baler drive arrangement including components that operate such that when power to the main power shaft is cut off, the plunger and auxiliary functions stop immediately, with only the flywheel of the plunger drive remaining in motion.
A more specific object of the invention is to provide a baler drive arrangement, according to a first embodiment, including a plunger and auxiliary functions that are hydraulically driven, with power from the main power shaft being split, with one path going through a flywheel clutch to a flywheel and then to a plunger drive pump, and with another path going to drive one or more pumps for supplying pressure fluid to hydraulic auxiliary function drive components.
Another specific object of the invention is to provide a baler drive arrangement, according to a second embodiment, wherein power flow from a main power shaft goes through a power splitting transmission so as to be divided between a plunger drive shaft, which carries a flywheel, and an auxiliary function drive shaft, with a normally-engaged, plunger drive control clutch being coupled between the flywheel and a plunger drive arrangement and wherein, either an one-way clutch is provided between the power splitting transmission and the flywheel, or a normally-engaged, auxiliary function drive control clutch is provided between the power splitting transmission and the auxiliary function drive arrangement. In both cases, the normally-engaged clutches are controlled so as to become automatically disengaged in response to power being cut off to the main power shaft.
Still another specific object of the invention is to provide a baler drive arrangement according to a third embodiment wherein the flywheel is mounted to a main power shaft that is coupled to a power splitting transmission for splitting power between a plunger drive shaft and an auxiliary function drive shaft, and wherein a normally-engaged coupling device is located between the flywheel and the power splitting transmission and operable for automatically disconnecting power to the power splitting transmission, and, hence, to the plunger and auxiliary function drive shafts in response to power to the main power shaft being shut off.